Hollow spheres of MgFe₂O₄ as anode material for lithium-ion batteries

Graphical abstract: Sub-micrometer hollow spherical MgFe₂O₄ was prepared via a solvothermal method without subsequently annealing process. Morphological characterizations show that there are large quantities of hollow spheres with the size of around 300 nm. And the particle size is relatively uniform. Its first discharge specific capacity at 0.1 C (107.2 mA g⁻¹) is 1344 mA h g⁻¹ with an initial irreversible capacity loss of about 28%. The capacities stabilize at around 900 mAh g⁻¹ with a coulombic efficiency of nearly 98% after 70 cycles. - Abstract: Sub-micrometer hollow spherical MgFe₂O₄ was prepared via an environmental friendly one-step solvothermal method without subsequently annealing process. And the synthesis mechanism was elucidated. It was found that formation of the hollow spherical MgFe₂O₄ needs at least two processes: the self-assembly of the nano crystal particles and the Ostwald ripening. The MgFe₂O₄ electrode exhibits excellent electrochemical performance. The capacity stabilizes at about 900 mAh g⁻¹ with a coulombic efficiency of nearly 98% at a current density of 107.2 mA g⁻¹ after 70 cycles. The superior performance could be attributed to the unique hollow structure.